rcourtman ee0e89871d fix: reduce metrics memory 86x by reverting buffer and adding LTTB downsampling ...

The in-memory metrics buffer was changed from 1000 to 86400 points per
metric to support 30-day sparklines, but this pre-allocated ~18 MB per
guest (7 slices × 86400 × 32 bytes). With 50 guests that's 920 MB —
explaining why users needed to double their LXC memory after upgrading
to 5.1.0.

- Revert in-memory buffer to 1000 points / 24h retention
- Remove eager slice pre-allocation (use append growth instead)
- Add LTTB (Largest Triangle Three Buckets) downsampling algorithm
- Chart endpoints now use a two-tier strategy: in-memory for ranges
  ≤ 2h, SQLite persistent store + LTTB for longer ranges
- Reduce frontend ring buffer from 86400 to 2000 points

Related to #1190

2026-02-04 19:49:52 +00:00

..

ADAPTIVE_POLLING.md

docs: update documentation after sensor proxy deprecation

2026-01-21 12:00:59 +00:00

METRICS_DATA_FLOW.md

fix: reduce metrics memory 86x by reverting buffer and adding LTTB downsampling

2026-02-04 19:49:52 +00:00

PROMETHEUS_METRICS.md

docs: standardize markdown syntax and remove deprecated sensor-proxy docs

2026-01-20 09:43:49 +00:00